Otago Daily Times - 'Draining the swamp' our issue too

The answer to our water quality issues lies in the soil, Ken Calvert  writes.

United States President Donald Trump is  n hot water for wanting to ‘‘drain the swamp’’.  

But, to strain the metaphor, our nation’s dairy farmers  are also getting themselves in trouble because they, and their ancestors, have  done just that.

The Southland plain is rich, green farmland because my great-grandfather, and  other  pioneers,  worked  hard to turn the flax, rushes, water, manuka and matagouri into prosperity.

But the  thousands of kilometres  of drains  they  created are now almost a liability.  The only thing between our excretory livestock and our recreational waterways  is a foot of  topsoil. 

We want our rivers to run clean but not green. We want to stay healthy, too. Nasty faecal coliforms that can make us sick  should have no place in our waterways.

It is nature, the ‘‘earthworms’’ and  micro-organisms  below them in the food chain, we must rely on.              

So, what’s the problem given the biological content of our soils? 

There is a rapidly escalating body of experience, from the ‘‘biological’’ farming fraternity  that fingers the overuse of highly soluble,  quick-acting fertilisers.

It only takes 3% of salt in seawater to make it undrinkable, and less than that of  the likes of urea and super phosphate,  to sicken something along that soil food web or food chain  and upset the system.   

There are much less soluble and slower-acting fertilisers that will still tick all the boxes and keep our earthworm population, nature’s drainage system, busy.  It’s not more antiseptics, disinfectants and fancy chemicals (they only add to the problem), it is soil biology and one foot of fertile topsoil that can come to our rescue.

●Ken Calvert is president of the Southland Worm Breeders Association.